1. Field of the Invention
The present invention relates to an electrical connector configured to hold a signal transmission medium inserted inside the body of the connector with a locking portion.
2. Description of the Related Art
Conventionally, electrical connectors electrically connecting a signal transmission medium such as a flexible flat cable (FFC) or a flexible printed circuit (FPC) to a circuit/wiring board have widely been adopted in various electrical devices and the like. The electrical connector is mounted on the circuit/wiring board via a board connecting leg (hold-down), for example, joined to the board so that the body of the connector stands upright from the surface of the circuit/wiring board. A signal transmission medium is inserted into the electrical connector from an insertion opening formed in the connector body for establishing electrical connection.
Some electrical connectors, specifically known as Non-Zif type, often employ an automatic locking mechanism for the signal transmission medium to stay inserted, with a locking portion provided in the electrical connector engaging with a positioning portion, which is for example a cut-out recess, provided to a terminal portion at the inserted end of the signal transmission medium inserted into the connector.
Conventional electrical connectors of this type (Japanese Patent Application Laid-Open No. 2001-196130) often employ a configuration that does not use a slider for achieving a necessary contact pressure between contacts held inside the connector and respective lands on the signal transmission medium (FPC) but instead uses a pivotally mounted lock lever that can prevent the signal transmission medium from coming off even with a small contact load. Since the locking portion provided to the connector body is a separate component, such a configuration tends to increase the entire cost of the connector due to an increase in the number of components. Another problem is that the locking portion is configured to engage with the signal transmission medium by its own weight, because of which the signal transmission medium cannot be held with a sufficient retaining force.
Another configuration proposed for conventional connectors (Japanese Patent Application Laid-Open No. 2003-100370) uses resilient support pieces provided to metal reinforcing parts attached to both ends of the housing and soldered to the circuit/wiring board for resiliently pressing and supporting the signal transmission medium (FPC) to prevent the FPC from displacing out of position. However, since the pressing force from the resilient support pieces is applied in a direction offset from the position where the metal reinforcing parts are soldered, after unlocking of the locking portion is repeated a number of times, the mounting state of the connector body may be adversely affected by the unlocking force continuously applied thereto, which may make the electrical connection unstable.